Create a new layer
(“Alien Glow”) below.
Extend the selection
slightly,
feather it,
and fill it with the Glow color.

Create a new background layer filled with black.

16.3.2. Activate the filter

You can find this filter in the image window menu under
Filters → Alpha to Logo → Alien Glow.

16.3.3. Options

Figure 16.346. “Alien Glow” options

Glow size (pixels * 4)

This is actually the font size option of the
“Alien Glow” Script-Fu script. However, two values
will be set in relation to this size: the glow will be enlarged by
“Glow size” / 30, and feather radius is
“Glow size” / 4. You should probably choose the
height of your objects for this option (ignore
“pixels * 4”).

Glow color

This is the color of the “eerie” glowing. Of course
it defaults to green (63,252,0), but a click on the swatch
button brings up the color selector where you can choose any
color.